Image Alt Text Checker

How It Works

Paste your HTML code or fetch a URL to scan all img tags. The tool checks each image for the presence and quality of alt attributes, categorizes them as Good (descriptive alt text), Missing (no alt attribute), or Empty (empty alt), and calculates an accessibility score (0-100%). It shows image source URLs, current alt text, and provides WCAG 2.1 compliance guidance for each issue found.

Why It Matters for SEO

Alt text is critical for both SEO and accessibility. Google uses alt text to understand image content and its relationship to the page topic — images with descriptive alt text can rank in Google Image Search, driving additional traffic. For accessibility, screen readers rely on alt text to describe images to visually impaired users. Missing alt text is one of the most common WCAG violations, affecting approximately 55% of images on the web according to WebAIM research.

When to Use This Tool

• Before publishing a page to ensure all images have proper alt text
• During accessibility audits to meet WCAG compliance requirements
• When optimizing existing pages for Google Image Search
• After a website redesign to verify image accessibility
• For e-commerce sites to improve product image SEO
• When auditing user-generated content for missing alt attributes

Key Concepts

Best Practices

• Write descriptive, specific alt text for every meaningful image
• Keep alt text under 125 characters — screen readers may cut off longer text
• Include relevant keywords naturally, but don't keyword-stuff
• Use empty alt='' for decorative images (icons, backgrounds) — this tells screen readers to skip them
• Don't start alt text with "Image of..." or "Photo of..." — screen readers already announce it as an image
• For complex images (charts, infographics), provide detailed alt text or link to a text alternative

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Frequently Asked Questions